Just want to share the importance of having a level tank.
Last week my wife called me at work (I actually live in another city because of work) to tell me that the marine tank was making funny noises and the water level was low.
I told her to check around because the water shouldn't be low and she said there was a crack in the glass. I hung up the phone and made that 2 hour drive in an hour.
Everything was fine, Hisami did a good job 'slowing' the leak untill I was able to get there. Little to no water damage. After looking at the crack in the Nisso, I knew right away it was because the tank was not level. (Right down the curved side on the left).
Level those tanks people!